Wheel immobilization devices are employed in a variety of situations, most commonly being the wheel chock. Wheel chocks provide an easy and inexpensive way to ensure that a vehicle will remain at rest if a parking brake should fail. Often chocks will have a triangular or rectangular cross section, the former being the preferred shape because it approximates the shape of a tire and thus provides a greater assurance of immobility. Wheel chocks are frequently used to restrain large trucks, mobile support equipment, or in the case of the present invention, aircraft.
It is common practice at most airports to provide chocks and/or tie-down means at aircraft parking and staging areas to prevent aircraft from rolling due to uneven pavement surfaces or wind impingements. More specifically, chocks prevent horizontal motion, while tie-downs generally prevent vertical motion, for example lift generated by high ground winds. Thus, chocks and tie downs provide sufficient immobilization for small aircraft. Larger aircraft generally do not require tie downs since ground winds have a reduced effect thereon, due to their increased weight. Tie-downs also may be capable of providing sufficient rolling impedance for smaller aircraft if chocks are not available.
After the Sep. 11, 2001 terrorist attacks on the United States, it became painfully evident that America's aircraft and airports are in need of greater security measures. One area that requires more security are airports that serve private pilots and business jets. Even though security has been increased as a result of the terrorist attacks, there are still gaping holes that may allow a terrorist with the proper skills to steal an aircraft and reek havoc. Moreover, many small airports are not completely surrounded by fences or walls, and door locks of many small planes are notoriously easy to circumvent. A would-be terrorist could easily gain access to the aircraft parking area, remove the chocks and tie-down chains, gain access to an aircraft, “hot-wire” the ignition, and take off. Since many single engine aircraft are light weight and have low wing loading, a runway take off may not be necessary, such that a taxiway would suffice to enable the aircraft to become airborne. Thus, an aircraft could be in the air before ground or tower controllers realize that the aircraft had been stolen. Even though one small single-engine aircraft may not do much damage, many coordinated aircraft would do great damage to a building, sports venue, or other structure.
An aircraft may be locked via the tie-down means. Chain or cable tie-downs, which interconnect wing attachment points to the ground, may be integrated with locks in order to prevent unauthorized movement of an aircraft. Unfortunately, many of these types of tie-downs are prone to rust and are easily cut. Alternatively, the attachment hardware on the aircraft could be removed. Finally, many small airports employ rope tie-downs which provide no protection against theft.
Propeller locks are another means of preventing unauthorized use of an aircraft. However, propeller locks may be undesirable to employ because generally they are heavy, cumbersome, difficult to install and remove, and are apt to damage the propeller during installation and removal. In addition, propeller locks only prevent movement of the propeller, the wheels of an aircraft utilizing such a lock may be moved, wherein the aircraft may be stolen. Finally, propeller locks are useless in conjunction with jet aircraft.
The foregoing is mainly concerned small private aircraft, but theft can foreseeably occur with respect to larger aircraft or other types of vehicles, although the sophistication of a thief or terrorist may necessarily be greater. Theft of business or jumbo jets may foreseeably occur, which are capable of causing great damage. Finally, as was the case in the Oklahoma City bombing, trucks have been used in the past as weapons of terror.
Thus, there is a long felt need in the field of wheel immobilization to provide an apparatus that is capable of locking interconnection with a vehicle to prevent theft while ensuring vehicle immobility. More specifically, it has been an urgent need to provide a means to secure parked aircraft so that they do not become potential terrorist weapons. The following disclosure describes a locking chock that is adapted to immobilize an aircraft by selectively interconnecting with a tire thereon.